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Practical 3: NDVI time-series over

a single region

Joseph White

shorturl.at/iFLNV

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Practical 3: Learning Objectives

  1. Mask clouds from an image collection
  2. Write a custom function
  3. Map it over a collection
  4. Plot a time-series
  5. Export data as a csv or image

Image Credit: NASA

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Cloud Masking

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Cloud Masking

sentinel-hub blog: https://bit.ly/2ROe2t7

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Cloud Masking

1. Cloud Coverage Assessment

2. Quality Assessment bands

MODIS, Landsat & Sentinel all have these properties.

But… they have different names

Yes/No

Percentage

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Cloud Masking

3. S-2 Cloud Probability

https://developers.google.com/earth-engine/datasets/catalog/COPERNICUS_S2_CLOUD_PROBABILITY

Probability

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Original Image

Cloud Mask

Masked Image

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Custom functions

Input → Operation → Output

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Charts

EE charts: https://developers.google.com/earth-engine/guides/charts_overview

Google charts: https://developers.google.com/chart/interactive/docs

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Access the code for the practical:

https://code.earthengine.google.com/93e7bab75a9d892c851b31e9c8374f05

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